1. Field of the Invention
The present invention relates generally to a handle assembly for a surgical instrument having at least one axially movable control member. More particularly, this invention relates to a proximal handle assembly for an endoscopic biopsy instrument.
2. Description of the Related Art
Endoscopic biopsy procedures are performed with an endoscope and an endoscopic biopsy instrument. An endoscopic biopsy instrument is a flexible medical device for insertion into a body passageway or cavity that enables a surgeon at a remote external location to remove and retrieve a tissue sample from a site internal to the patient""s body. The biopsy instrument typically includes an elongated flexible member having a tissue sampler at the distal end and a handle assembly with a manual actuator at the proximal end.
During a biopsy tissue sampling operation, a surgeon guides the endoscope to the biopsy site within the body of the patient. The biopsy instrument is then inserted through the endoscope until the tissue sampler is proximate to the tissue to be sampled. The surgeon manipulates the actuator so that the tissue sampler tears or cuts away a sample of tissue from the biopsy site and retains the tissue sample.
Most endoscopic biopsy instruments have one or more control members, such as wires, extending through a flexible conduit typically having a wire coil. A distal end of each control member is typically connected to a tissue sampler or some other form of end effector located at a distal end of the flexible conduit. A proximal end of each control member is connected to the actuator of the proximal handle assembly such that movement of the actuator causes axial movement of the control members and thereby actuates the tissue sampler. For example, distal movement of the control members causes opening of jaws of the tissue sampler and proximal movement of the control members causes closing of the jaws, or vice versa.
There are a variety of drawbacks and disadvantages associated with some conventional handle assemblies for surgical instruments including endoscopic biopsy instruments. For example, some of these assemblies have a number of separate components that must be assembled together in relatively costly and or complex manufacturing processes. In one conventional handle design, the control members are attached to the actuator of the handle assembly via an anti-kinking member, set screw, and a cross pin which is configured to be placed in the actuator. The control members are passed through the anti-kinking member and the set screw is tightened in the cross pin to attach both the control members and the anti-kinking member to the combination of the cross pin and the actuator. Although such a configuration provides an effective attachment of the control members to the actuator, it could be less expensive if the number of parts was reduced.
Attachment of the handle assembly to the flexible conduit is another aspect of surgical instruments that could be improved. Various apparatuses have been used to attach the flexible conduit to the handle assembly. Considerations include cost, ease of component manufacture, ease of assembly, expected life cycle of the biopsy instrument, operational loads, and acceptance by the operator. Surgeons would find unacceptable any attachment apparatus that permits the flexible conduit to move relative to the handle during manipulation of the end effectors.
One method of attaching the coil to the handle is bonding. This may be acceptable for disposable biopsy instruments, but not for instruments that are to be autoclaved. Repeated autoclaving may degrade the bondline. Furthermore, bonding raises OSHA/SHEA concerns regarding the exposure of assembly workers to solvent fumes.
In another example, a barbed crimp band is crimped onto the end of the flexible conduit and press fitted into an inner bore of the handle. Such an assembly could be improved if it was less expensive. Additionally, press fitting the barbed crimp band into the handle may also result in unacceptably large tensile hoop stresses in the handle that may ultimately lead to cracks. Furthermore, this design might create an undesirably large gap between the outer diameter of the flexible conduit and the inner bore of the handle, leaving the flexible conduit unsupported within the handle and prone to bending displacements.
The present invention is directed to structural arrangements and methods that optionally obviate one or more of the limitations of the related art. As embodied and broadly described herein, one aspect of the invention includes a handle assembly for a surgical instrument having a flexible conduit and at least one control member axially movable with respect to the flexible conduit. The handle assembly includes a body member configured to be coupled to the flexible conduit. An actuator is movable on the body member. The actuator includes at least one projection member. The assembly further includes a reinforcement tube having an interior passage sized to accommodate the control member. The reinforcement tube includes at least one bend configured to engage the at least one projection member such that movement of the actuator with respect to the body member causes movement of the reinforcement tube.
As used herein, the term xe2x80x9csurgical instrumentxe2x80x9d is not limited to instruments used in what are sometimes considered to be surgical procedures. In particular, the term xe2x80x9csurgical instrumentxe2x80x9d relates to a variety of different forms of medical instruments used, for example, for a variety of differing bodily diagnoses and/or treatments.
In another aspect, the invention includes a handle assembly comprising a body member including portions configured to be connected together to retain the flexible conduit therebetween.
In yet another aspect, the invention includes a surgical instrument including the handle assembly, a flexible conduit coupled to the body member, and at least one control member axially movable in the flexible conduit. Preferably, at least one end effector is at a distal end of the flexible conduit. The end effector could be linked to the control member such that axial movement of the control member causes activation of the end effector.
In an even further aspect, the invention includes a method of making a handle assembly, the method includes placing at least one control member in a reinforcement tube, bending the reinforcement tube to form at least one bend in the reinforcement tube, the at least one bend reducing the interior cross-section of the tube and thereby retaining the control member in the reinforcement tube, and engaging the at least one bend with at least one projection member associated with an actuator movable on a body member such that movement of the actuator with respect to the body member causes movement of both the reinforcement tube and the control member.
In an additional aspect, the invention includes a method of connecting a handle assembly to a flexible conduit of a surgical instrument. The method includes providing a handle assembly including a body member and an actuator movable on the body member, wherein the body member includes portions configured to be connected together to retain the flexible conduit therebetween, placing the flexible conduit between the portions of the body member, and connecting the portions of the body member together to retain the flexible conduit therebetween.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention.